Conventional semiconductor process chambers, for example, such as etch chambers, typically utilize a substrate support having one or more rings (e.g. an edge ring) disposed atop the substrate support and configured to secure the substrate in a desired position during processing. However, the inventors have observed that conventionally used edge rings may comprise different thermal properties (e.g. different heating and cooling rates) compared to the substrate support, thereby causing temperature non-uniformities proximate the edge of the substrate, thus causing an undesirable non-uniform processing of the substrate. In addition, the edge ring may be heated to a higher temperature than the substrate support during processing due to heat generated by the process or by processing components, for example, such as an upper electrode (e.g., showerhead or ceiling), thereby leading to further temperature non-uniformities.
Thus, the inventors have provided an improved apparatus for processing a substrate.